Too many grills in the house will only harm you in the end. If there's a fire in your house, you can't get out quick enough. Hangus.
Too many CCTV's, fake or real, will only attract more attention. If I'm the robber, I'll target your house 1st.
I don't really know how you can really prevent them from breaking in though... I'll give my thoughts a go anyway
My suggestion is put TV, DVD player those cheap cheap things in the living room, put some as distraction can already. Then in your room put RM100 like that in your drawer. Usually when they get into your house they will ransack your living room then straight to your room. So those valuable things better hide in other places I guess

This way you lowered your lost by a large amount already.
I think if you set a special 2nd alarm outside your house will help too. The 1st alarm is inside the house, must be damn freaking loud until can scare the robbers soul run away. If that fails (the robbers disabled the alarm), then your 2nd alarm which is outside your house will do the rest. This 2nd alarm that sounds like police sirens will be activated 2 minutes after the break-in. So when the robbers inside your house heard the sirens surely they will run away
Make sure when that if the alarm goes off, it will inform you also. That way you will know if anything happened to your house. Hope these helped